Photographic color-forming compounds



Patented Feb. 15, 1938 Q PATENT OFFICE PHOTOGRAPHIO COLOR-FORMING CQM- POUND Leopold D. Mannes and Leopold Godowsky, Jr., Rochester, N.- Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No llrawlns.

, 11 Claims. This invention relates to photographic colorforming. compounds, and more particularly-to compounds which react with the oxidation product ofa photographic developer to form a colored compound in a photographic layer This applicationis' a continuation-in-part of our application Serial No. 8519, filed February 27, 1935.

It is known that colored photographic images may be formed by using a developer which forms a colored compound on development. The colored 1 compound thus formed is deposited adjacent the silver image during the development. It is also known that a colored image may be formed byadding to the developer solution a compound which combines with the oxidation product of the developer and forms a coloring substance. The production of colored photographic images in this way was described by Fischer in U. 3. Patent No. 1,102,028, June 30, 1914. Many of the coupler compounds described by Fischer were, however,

' sensitive to sulfite in the developer, and for this reason, Fischer recommended using them in developers containing no sulflte. It is a recognized fact that sodium sulfite, or other sulflte, is a highly desirable constituent of photographic developers, since it tends to prevent oxidation of the developing agent by air. The color-forming developers suggested by Fischer were, therefore, unstable, and were found to oxidize readily on use.

It is therefore an object of the present invention to provide a photographic developer which produces a colored compound simultaneously and in situ with-photographic development, and which is not readily oxidized by air on development. A further object is'to provide novel coupler compounds forcolor-forming development.

These objects are accomplished by the present.

inventionby the use of aromatic diamino developers together with certain specific coupling comv I pounds hereinafter described.

When a silver halide emulsion containing a.

latent photographic image is developed, the silver halide is reduced to metallic silver and the de-- veloping agent is oxidized. The aromatic diamine tion or incorporated. in the emulsion layer, a dye is formed by the coupling' of thiscompound with the oxidationproduct of the aromatic diamino compound and is deposited in the'gelatin or other silver halide carrier adjacent to the metallic silver grain. The dyes thus formed do not readily Application December 15, 1936, 86ml N0. 115,972 I wander from the place of formation. The couplers may be soluble or insoluble in water, but the water or alkali-soluble couplers are preferably used. The dyes are not physically. attached to the silver grain, so that the silver may be sub- 5 sequently washed out of the carrier layer leav-- ing a pure dye image. I

The aromatic amino compounds which may be used as developers in our process include the mono-, di-, and triamino aryl compounds-and compounds formed therefrom by substitution in the amino group as well as in the ring, such as alkyl phenylene diamines and alkyl toluylene diamines.. These compounds are usually used in the salt form, such as the hydrochloride or the 16 sulphate which aremore stable than the amines themselves. Examples are diethylparaphenylene diamine hydrochloride, monomethylparaphenylene diamine hydrochloride, and dimethylparaphenylene diamine sulphate. These compounds 20 have an unsubstituted amino group which enables the oxidation product of the developer to couplewith the color-forming compounds.

The coupling or color-forming compounds which we contemplate using are acetoacetamides or cyanoacetamides containing areactive methylene group. The colored compounds formed on development result, we believe, from a coupling of the yoxidation" product of the developer to the color-forming compound at its reactive methylene group. Although our invention is not to be taken as restricted by this explanation of the chemical reaction involved, our present knowledge indicates that the colored compounds are formed in this way.

The color-forming compounds which we have found to be useful include compounds having the general formula where Y is an aceto CH3CO) or an cyano (CN,-') group and R. is organic radical such as an' aryl or an azole group.

Among the compounds 'which we may use, where Y: aceto and R=an aryl group, are acetoacetanilide i its chain-substituted derivatives, such as. a-bromoacetoacctan'ilide; and its ring-substituted derivatives, such as acetoacet-p-bromanilide, acetoacet-2-chloroanilide, acetoacet-2,4-dichloroani-.-

2 v lide, acetoaoet-2,5-dichloroanilide, acetoacet-mnitroanilide, o-methoxy acetoacetanilide, p-hydroxy acetoacetanilide, acetoacet-p-anisidide,

acetoacetyl-fl-naphthylamine:

and its sulfonate, sodium acetoacet-2-naphthylamine-'l-sulfonate. Also p-phenylazo acetoacetanilide:

and 2-acetoac'etamino anthraquinone:

Where Y =aceto and R=an azole group, we may use l-acetoacetamlno benzothiazole:

and the corresponding phenyl thiazole. Also 2- aceto-acetaminol-methyl carbethoxy. thiazole:

and 2-acetoacetamino-4-(1 coumaronyl) -thiazole:

Where Y=cyano and R=aryl, we may use cyanoacetanilides, of which cyanoacetanilide itself is an example:

o GN-CE-(LNHQ Where the aryl group comprises more than one ring, we may use compounds such as cyanoacetp-naphthalide o err-om--mr The following examples, which are illustrative only, indicate typical developer solutions made according to our invention:

Example I A. Diethyl p.phenylenediamine HCl g 4 2 Sodium sulfite g 5 Sodium carbonate g 30 Water to cc 1,000 B. p-bromoacetoacetanilide g 2 Acetone cc 50 Add 13 to A.

Example II A. Dimethyl p.phenylenediamine sulphate g 1 Sodium sulflte g 2 Sodium carbonate g 30 Water to cc 1,000

B. 4-nitroacetoacetanilide l g 2.5

Iso-propyl alcohol cc 100 Add B to A Our process may be employed for the production of colored photographic images in layers of gelatin or other carrier, such as collodion or an organic ester of cellulose. The carrier may be supported by glass or a flexible film, such as cellulose nitrate, cellulose acetate, or other cellulose ester. Theemulsion may be coated as a single layer on the support, or as superposed layers on one or both sides of the support. The superposed layers may be difierentially sensitized, and dyes formed therein may be bleached by an oxidizing agent, such as chromic acid, to colorless, soluble compounds. The destruction of the dye in this way does not destroy the silver image, and a silver image may be colored, bleached, and recolored a number of times, thus permitting the formation of natural-colored images in superposed layers, as described in ourv prior application, Serial No. 8516.

Although we have referred in the specific examples to the use of our coupler compounds in the developing solution, it is also possible to incorporate them in the sensitive emulsion layer. The silver salt may be combined with the colorformer to form a silver salt of the color-former, the color-former may be absorbed or adsorbed to the sensitive salt, or the color-former may in certain cases, merely be dispersed in the gelatin of 2. A color-forming photographic developer comprising an. aromatic amino developing compound and a coupler compound having the general formula 0 Y-CHr-il-NHR where Y is selected from the class consisting of aceto and cyano groups and R. is selected from the class consisting oi aryl and azole groups,

3. A color-forming photographic developer comprising an aromatic amino-developing compound and an acetoacetamide coupler compound with which the developing compound is capable of reacting on development. a

- 4.- A color-forming photographic developer comprising an aromatic amino developing compound and a eyanoacetamide coupler compound with which the developing compound is capable of reacting on development.

5. A color-forming photographic developer comprising an aromatic amino developing comcomprising an aromatic amino developing compound and an acetoacetamino azole coupler compound with which the developing compound is capable of reacting on development.

7. A color-forming photographic developer comprising an aromatic amino developing compound and para-bromo-acetoacetanilide.

8. A color-forming photographic developer comprising a pa'raphenylenediamine developing compound and angacetoacetanilide.

9. The method of developing a colored image in a gelatino-silver halide photographic layer, which comprises coupling the development product of an aromatic amino developing compound with an acetoacetamide coupler compound simultaneously with the development 0! a silver image inthe layer.

10. The method of developing a colored image in a gelatino-silver halide photographic layer,

which comprises coupling the development prodnot of an aromatic amino developing compound with a cyanoacetamide coupler compound simultaneously with the development of a silver image in the layer. Y i

11. The method of developing a colored image in a geiatino-silver halide photographic layer.

, which comprises coupling the development product or an aromatic amino developing compound with an acetoacetanilide simultaneously with the development 01' a silver image in the layer;

LEOPOLD D. MANNES. LEOPOLD GODOWSKY. Jli. 

